1. The first thing you need is a jailbroken iPhone 4S, and to my knowledge an iPhone 4S jailbreak isn’t even publicly available yet. iPhone Dev Team, the group that usually releases iPhone jailbreaks, says the hack still needs lots of work before it can go public.

2. You also need “files from an iPhone 4S which aren’t ours to distribute,” the hacker, Steven Troughton-Smith, told 9to5Mac. And Troughton-Smith isn’t even interested in bringing Siri to a jailbroken app store such as Cydia. He’s only out to prove that the technology works on older devices. Anyone who does distribute Siri without Apple’s permission would be breaking the law.

3. To function, Siri must communicate with Apple’s servers. So even if you somehow got Siri working on an iPhone 4, there’s no guarantee that Apple won’t figure out how to detect unauthorized users and shut them down.

The bigger takeaway from this development, as CNet points out, is simply that the iPhone 4 can technically run Siri. This seems to confirm the cynic’s view that Apple is withholding the software so more people buy the iPhone 4S.

I have an alternate theory: Because Siri puts demand on Apple servers, Apple is limiting the software to new devices to prevent the servers from getting overwhelmed. That might’ve been the right call, given reports of Siri not responding for some iPhone 4S users.

In any case, don’t get your hopes up for hacking Siri onto an iPhone 4, iPod Touch or iPad. Even though it’s technically possible, there’s still a lot of work to be done, all of which could be wiped out by Apple anyway.